Consultation about units setting in uncertainty analysis in BioSTEAM

[zasddsgg]

Hello, could I ask you some questions about units setting in uncertainty analysis in BioSTEAM. Thanks for your help. Wish you a good day.

1. In https://biosteam.readthedocs.io/en/latest/tutorial/Uncertainty_and_sensitivity.html#:~:text=Internal%20rate%20of%20return%20%5B%25%5D%20%20%200.137, the unit has been marked %, why is the IRR result still 0.13?

2. For @param(name='Gypsum split', element=S402, kind='coupled', units='') (https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/lactic/models.py#L405), why are the units not % but ‘’?

[yalinli2]

Well it might be confusing, but IRR should be 13%, we probably shouldn't include % in the unit. Unit being '' just means the numbers are fractions, there are no units.

[zasddsgg]

In https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/lactic/models.py#L405#L396-L397, % is added to the unit, but the value is still used as a decimal?

[yalinli2]

Yes it's used as a decimal. For questions like this, you can figure out the answer yourself by looking at the raw code of the unit.

[zasddsgg]

But the units are %, so is 0.07% the same as 0.0007? Other numbers are similar, such as Enzymatic hydrolysis solids loading at 0.2% (https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/lactic/models.py#L405#L334) and Enzymatic hydrolysis glucan-to-glucose at 0.9% (https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/lactic/models.py#L405#L353)? Is it a violation that the upper and lower limits of the parameters are orders of magnitude the same as the baseline?

[yalinli2]

OK see a32ed48, I updated the unit so it's less confusing.

[zasddsgg]

I got it. Thank you for the update.